The recovery of Testosterone spiked to levels throughout the range of the assay in various matrices was evaluated.
Average % Recovery
Cell Culture Media (n=4)
EDTA Plasma (n=4)
Heparin Plasma (n=4)
To assess the linearity of the assay, samples containing and/or spiked with high concentrations of Testosterone were serially diluted with Calibrator Diluent to produce samples with values within the dynamic range of the assay.
Preparation and Storage
Store the unopened product at 2 - 8 °C. Do not use past expiration date.
Testosterone is an important secreted androgen synthesized from cholesterol-derived pregnenolone. Circulating testosterone is predominantly bound to proteins, including specific sex hormone binding globulin (SHBG) and nonspecific proteins such as albumin. It is believed that bioavailable testosterone includes the free steroid and the albumin-bound form. Testosterone is the main androgen secreted by the Leydig cells of the testes and affects both primary and secondary sexual development.
Refer to the product for complete assay procedure.
Bring all reagents and samples to room temperature before use. It is recommended that all samples, standards, and controls be assayed in duplicate.
Prepare all reagents, standard dilutions, and samples as directed in the product insert.
Remove excess microplate strips from the plate frame, return them to the foil pouch containing the desiccant pack, and reseal.
50 µL Primary Antibody Solution
Add 50 µL of Primary Antibody Solution to each well (except the non-specific binding (NSB) wells).
Incubate at room temperature for 1 hour on a horizontal orbital microplate shaker.
Aspirate each well and wash, repeating the process 3 times for a total of 4 washes.
Add 100 µL of Calibrator Diluent to the NSB wells.
Add 100 µL of Calibrator Diluent to the zero standard (B0) wells.
100 µL Standard, Control, or Sample
Add 100 µL of Standard, control, or sample to the remaining wells.
50 µL Conjugate
Add 50 µL of Conjugate to each well. Cover with a plate sealer, and incubate at room temperature for 3 hours on the shaker.
200 µL Substrate Solution
Add 200 µL Substrate Solution to each well. Incubate at room temperature for 30 minutes on the benchtop. PROTECT FROM LIGHT.
50 µL Stop Solution
Add 50 µL of Stop Solution to each well. Read at 450 nm within 30 minutes. Set wavelength correction to 540 nm or 570 nm.
R&D Systems personnel manually curate a database that contains references using R&D Systems products.
The data collected includes not only links to publications in PubMed,
but also provides information about sample types, species, and experimental conditions.
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Does R&D Systems® Testosterone Parameter Assay Kit, Catalog # KGE010, detect free or total testosterone?
'Free' testosterone is typically defined as testosterone which is bioavailable, and not bound to sex hormone binding globulin (SHBG). Interference testing performed by spiking SHBG into testosterone-containing samples, demonstrates interference in testosterone detection with Catalog # KGE010, when the concentration of SHBG is greater than 100 ng/ml. (For further details on interference testing, please refer to the "Specificity" section in the product insert.)
Assays for 'total' testosterone measure both 'free' testostrone as well as testosterone bound to SHBG. Since KGE010 does not detect testosterone bound to SHBG, this assay does not measure 'total' testosterone.